Improvement in cutting screws on rails of bedsteads



PATENT Orti-cl2o SPENCER LEVIS, OF TIFFIN, OI-IIO.

IMPROVEMENT IN CUTTING SCREWS ON RAILS OF BAEDSTEADS.

Specification forming part of Letters Patent No. 5,812, dated September26, 1848.

To @ZZ whom it may concern:

Be it known that I, SPENCER LEWIs,of Tiffin,

in the county of Seneca and State of Ohio,

have invented certain new and useful Improvements in Machinery forCutting Screws on Rails and in Posts of Bedsteads, of which thefollowing is a full, clear, and exact description, reference being hadto the annexed drawings, making part of this specification, of Which-Figure l is a top view of the machine for cutting screws on the tenonsof the rail, showing the several parts in connection. Fig. 2 is avertical longitudinal section of the same. Fig. 3 is a verticaltransverse section through the line .fr Fig. l is a longitudinal sectionthrough the middle of the tube in which the cutters are held. Fig. 5 isan end view of t-he same. Fig. 6 is an end elevation of the machine forcutting the screws in the posts. Fig. 7 is a vertical longitudinalsection of the same, taken through the line #55! of Fig. 6. Fig. S is anenlarged view of the end of the mandrel, showing the cutters affixedthereto.

Vhen the same parts occur in the different figures they are designatedby the same letters of reference.

The most difficult point in the construction of bedsteads fastened byscrews cut on the tenons of the rail and iu the mortises of the postshas heretofore been to cut the thread of the screw up to the shoulder ofthe tenon on the rail. This object, never heretofore effected by ascrew-cutting machine, is fully accomplished by my invention, which issimply a cutter of a peculiar form arranged even with the open end ofthe common tubular cutter-holder in advance of the ordinary critter,being, together with the ordinary cutter, secured in the usual manner tothe interior surface of the tube. Thus my invention effects a veryimportant result by the most simple means. I have also made otherimprovements which greatly facilitate the manufacture of bedsteads,which consist in the combination and arrangements of the several partsof the machine by which the right and left screws are cut simultaneouslyou the respective ends of the rail, and likewise in the combination andarrangement of cutters, mandrels, and clamps, by which the female screwsare cut in the mortises in the adjacent sides of the posts by clampingit but once and without varying its position, whereas by all thedifferent modes heretofore practiced the position of the posthad to bechanged and it is necessary to clamp it twice.

To those who are acquainted with the subject a comparison of my machinewith others that have been made for the same purpose will demonstratethe fact that by means of my invention bedstead-fastenings are made moredurable and accurate, and at the same time that they are made cheaperthan they can be made by any other means.

A, Figs. l and 2, is the base or platform of the machine for cutting thescrews on the tenons of the rails. This platform is made of plank of anoblong rectangular form and of any suitable dimensions. In each end ofthe platform a vertical slit is made for a guide for the carriages whichslide upon it. In one of the slits or mortises the screw B3 is placed.It turns in boxes formed in either end of the mortise.

On the outer end of the screw the handwheel B5 is secured. This screw isfor the purpose of adjusting the carriage B', to which it is connectedby a female screw formed in the stud BG, which projects from the lowerside of the carriage. Upon the platform the carriages B B are placed.They may be moved rvlongitudinally toward or from each other for thepurpose of being adapted to'cutting the screws on rails of differentlengths. The carriage B, when adjusted, is secured in its position bythe screw-bolt B4, and the carriage B is both adjusted and secured inits position by the screw B3. Upon the carriages the standards C C C Cand the clamps D D are erected. The standards G C have boxes formed intheir upper ends,in which the outer ends of the mandrels F F turn. Onthe upper ends of the standards C C female screws are formedcorresponding to the male screws F2 of the mandrels which turn in them.The mandrels F are made of any suitable material and dimensions, havingcog-wheels F secured to them, by which they are turned. Lead-screws F2,corresponding in pitch with the thread required to be cut on the tenonof the rail, are formed ou the central part of them, and metallic tubesG, to hold the cutters, are secured on their inner ends. These tubescorrespond in internal diameter with the external diameter of thetenons, which, during the operation of having the screws cut on them,pass into the tubes.

The cutters c c', Figs. 2, 4, and 5, are secured to the inner surface ofthe tube in the line of the thread of the screw in any convenient andsubstantial manner, the cutter c being even with the outer end of thetube and of course in advance of the cutter c. The cutter c', inexternal form, resembles an oblique threesided pyramid, having one sideperpendicular to its base, which is the usual form of cutters for makingthe triangular threads of screws. The vertical side is of the form of anisosceles triangle, and on its sides are formed the cutting-edges.

The cutter c, which I shall call a semi-cut ter, corresponds inmagnitude and form with half of the cutter c divided by a plane passingthrough it vertically, through and at right angles to its perpendicularside. The cuttingedges of this cutter form a right-angled triangle theperpendicular of which is placed even with the outer end of the tube andon the center line of the thread of the screw on the interior of thetube, which of course corresponds with the space between the threads ofthe screw on the tenon. The cutting-edges of both these cutters are ofthe usual form, as are also the apertures in the side of the tubethrough which the chips or shavings pass from the cutters. Thesemi-cutter is made and arranged as above described for the purpose ofcutting a semi-thread on the tenon adjacent to the shoulder where thereis not space sufcient for a full thread, and thus making the screw ofthe tenon accurately corresponding to the female screw in the post, sothat when the post and rail are screwed together the joint between themshall be close and accurate.

The clamps D D are each composed of two jaws held together by the hooksa ct and joined to the carriages by hinges Z) b, Fig. 3. These clampsare for the purpose of holding the rail at the required elevation tobring the tenons concentric with the circle in which the cutters revolveand to hold it firm and rigid during the action of the cutters instarting the thread.

Near the center of the platform A, Fig. 2, the transverse guides E E areplaced, in which the clamp E slides. This clamp is for the purpose ofembracing the rail and firmly holding it, so that it may not turn duringthe operation of cutting the screws on its tenons.

The standards H H are secured to the platform A. On their upper endsboxes are formed in which the shaft H turns, on which is secured thecog-wheels H3 H3, which gear into the wheels F F of the mandrels. Theshaft Hl is turned bythe winch H2, which is secured to its end. The twowheels H3 H3 are both of the same diameter, as are also the two wheels FF', and the whole four wheels have cogs of the same pitch and turnsimultaneously.

The operation of this portion of the machine is as follows: Thestandards being adjusted to the length of the rail by means of theset-screw B3 and the clamp-screw B4, the rail is then secured in theclamps E and D D. The attendant now lays hold of the handle of the winchH2 and turns it, which turns the shaft H', the wheels, and the mandrelsand cutters which are connected with it. The screws on the mandrelscause them to move longitudinally when turned, advancing the cutterssimultaneously upon both ends of the tenons, cutting' the threads of thescrew on the same as they progress, the tubes advancing as fast as thethread is cut over the tenon. Vhen the cutter has progressed on thetenon to the shoulders c e of the clamps D D, the hooks a a are unloosedand the clamps opened entirely clear from the rail, in order that thecutters may progress to the shoulder of the tenons, the tubes nowholding the ends of the rail instead of the clamps. When the cuttershave been turned up to the shoulders e e of the tenons, the motion ofthe winch is reversed, which withdraws the cutters from the tenons. Thescrew is now completed, and the clamp E being loosened the rail is takenout to make way for another.

The machine for cutting the female screws in the mortises of the poststo correspond with the male screws on the tenons of the rails iscomposed of a bench K, Figs. 6 and 7, made of stout plank and of anyconvenient form and dimensions. This bench is supported by the legs J.To one end of the bench is secured firmly the block L, which supportsthe horizontal screw-mandrel M, and in which is made the female screw inwhich said mandrel turns. N is the clamp-head, which is adjustable toadapt it to the cutting of screws in the mortises of posts of differentsizes. One end of the head rests upon the block L. The other issupported by the set-screw P. It is held firmly against the post T, Fig.6, clamping the same tightly upon the bench J by the screw O, whichpasses through an oblong mortise g, the lower end of which screw turnsin a female screw f in the bench K. Through the end of the head adjacentto the block L a screw-mandrel Q passes down, turning in a female screwformed in said head. The mandrel Q stands at right angles to the mandrelM. The notch h and mortise g are respectively of sufficient length toadmit of the adjustment of the head, so as to cut the screws in themortises of posts of all sizes from the largest to the smallest. To theouter ends of the mandrels the Winches Q and M are respectively secured.By these Winches the mandrels are turned. To the inner end of each ofthe mandrels two cutters t' i' are secured. These cutters correspond inshape and magnitude with the cutter c', Figs. 4: and 5, and are placedupon opposite sides of the mandrels in the line of the helix formed bythe thread of the screw. The screw on the central part of the mandrelswhich turn in the head and in the block L corresponds in pitch with thescrew on the mandrels F, Figs. l and 2. .Y

The operation of cutting the female screws in the posts is performed asfollows: The mortises being bored in the post, it is clamped on thebench in the position seen at T, Fig. 6, the mortises being placedconcentric with the ends of the mandrels Q M. Preparatory to clampingthe post the mandrels are turned back until their inner ends are withinthe face of the head and the block L. The post is now laid in its properposition, the end of the head resting upon it. The set-screw P is thenturned until the head is rendered parallel to the top of the bench. Thescrew O is next turned down, which brings the head tight upon the post,which it holds With atirm grip. The attendant now lays hold of the winchM and turns it, which causes the mandrel M to turn,and as it turns it isadvanced by the lead-screw upon it, and as it advances the cutters aremoved forward into the mortise penetrating the wood on its concavesurface and cutting out the screw. Vthen the cutters have reached theybottom of the mortise, the motion of the winch is reversed, whichwithdraws them out of the mortise in which the screw is now completed.The 1nandrel Q, with its cutters, is now in like manner caused to cutthe screw in the mortise of the adjacent side of the post, which beingdone the screws in the post are completed. By this arrangement thescrews are cut in the post without altering its position from the timeit is clamped on the bench until the operation is complete. Thus notonly is much labor saved but the liability to the error of cutting thescrew with the Wrong thread 'is entirely removed. This accident inconsequence of the workmen being careless or confused hap` pens veryfrequently, and as the post is thereby irreparably spoiled it occasionsconsiderable loss.

I do not claim cutting screws on the tenons of rails of bedsteads bymeans of a V- shaped cutter Xed in a tubular holder; nor do I claimcutting the right-and-left screw on the tenons simultaneously; nor do Iclaim cutting thescrew in the post clamped in a frame or to a bench bymeans of a V-shaped cutter fixed to the outside or periphery of aholder, as these results have been produced by other means; but

What I do claim as my invention, and desire to secure by Letters Patent,is-

The combination and arrangement herein described of the half orsectional cutter c, secured on the end of the inner surface of thetubular holder, with the entire cutter c', also secured to the in nersurface of the holder for the purpose of cutting a sectional threadadjacent to the shoulder of the tenon on the end of the railcorresponding to the sectional thread cut on the outer end of the femalescrew in the post, so that the rail having a square shoulder and thethread of the screw cut on the entire length of the tenon may be screwedup tight against the face of the post, forming a close and perfectjoint, which cannot be effected by any other machine in use or known.

In testimony whereof I have hereunto signed my name before twosubscribing witnesses this 13th day of September, A. D. 184:7.

SPENCER LEWIS.

Witnesses:

WM. P. ELLIOT, A. E. H. J oHNsoN.

